On March 14, 2007, the United States submitted a proposal to adjust the Montreal Protocol to accelerate the phase-out of ozone-damaging chemicals. The U.S. proposal includes four elements that can be considered individually or as a package: accelerating the phase-out date of hydrochlorofluorocarbons (HCFCs) by 10 years; adding interim reduction steps; setting an earlier baseline; and phasing out the most damaging HCFCs to the ozone layer as the first priority.